buckb created a great plugin PerfMonPDH. He also opened it's sources so modifications are possible.
This topic is created for two reasons: this plugin is no more compatible with PerfMonPDH, and not many people will find it in the dozens of posts in the original topic.
I don't really like "PerfMonRxtd" as a name of a plugin but I haven't come up with better name.

Overview

PerfMonRxtd extends PerfMonPDH. It aims to replace old PerfMon and new UsageMonitor plugins.
All features of PerfMonPDH 2.0.1.3 are supported.
All features of PerfMon are supported.
All features of UsageMonitor are supported.

In comparison with PerfMonPDH there are some differences here and there, but the most important is support for custom expressions that allows you to use sorting and rollup with other things than just counters.
Other nice feature is the ability to pause data fetching while keeping updates of parent measure. It allows different sorting options on the same dataset, and anything other that can be achieved with changing options.

Skin shows approximate RAM usage (in the left) and approximate Commit usage (in the right). It is very rough but I don't know any better way, and seems like Google doesn't know either. Buttons in the upper right corner can pause data fetching and switch between sorting by RAM and Commit. Buttons in the upper left corner are used to show processes further than 1-7.

You can find other examples in the PerfMonPDH topic — plugins have different, but very similar syntax.

Fixed: child measures with RESULTSTRING_NUMBER have string value ""Fixed: sort by name works incorrectly with non ASCII lettersFixed: expressions rollup for min/max values solved incorrectlyFixed: expressions does not recognize floating pointer numbersFixed: some valid math expressions can't be parsed (e.g. "1 - 2 + 3")Fixed: some expressions can crash plugin (e.g. "-1")Fixed: very long process names could potentially crash plugin when using "GPU Engine" and "GPU Process Memory" objectsAdded: child option "SearchOriginalName"Added: child option "NameSource"Added: expressions now support "SearchOriginalName" and "NameSource"Added: WhitelistOrig, BlacklistOrig options: case sensitive, match original names instead of display namesAdded: "LogicalDisk" can be rolled up by mount folder (ported from PerfMonPDH 2.0.1.3, thanks to buckb for the idea and code)Changed: display name and rollup name merged into display nameChanged: black/white lists are case insensitiveChanged: "LogicalDisk" have three Display names: Original, DriveLetter, MountFolder. If Original is set then rollup can not be performed because all names are unique.Changed: "GPU Engine" and "GPU Process Memory": removed "Gpu" from display names. Old options are still supportedChanged: ResultString names: removed "Instance" part. Old names are still supportedChanged: removed counters max number limitChanged: if sortBy set to expressions, but no expressions found, then sort is set to none instead of breaking the measureChanged: LimitIndexOffset is set to false by default

"Fixed" explains a problem and means that this problem is no longer exists.
"Changed" explains new behavior.

Readme file was improved.
Example skin was missing a script file, which is now included into archive and .rmskin package.

Please, write here if you encounter any problems or bugs.

Plugin updated to version 1.1.1.
The only change is that now version in the dll is 1.1.0. I forgot to change version in the first upload.